First-level removable module having bar code I/O and second-level removable memory

ABSTRACT

Computer hosts, such as PDAs, are customized for use in bar code scanner applications through use of a first-level removable expansion module having bar code related circuitry and a slot and internal connector for a second-level removable memory. In combination with a connected or attached I/O device for scanning bar codes, these modules provide embedded bar code scanning I/O adapter and/or application-specific functions as well as second-level removable memory functions. The removable memory may be used to store a backup copy of the scanned data for restoration in the event the original scan data is lost or corrupted. Restoration may occur using any interface compatible with the removable memory. The removable memory may also be used by the bar code scanner application specific circuitry within the first-level removable expansion module. In illustrative embodiments, an industry standard physical and electrical interface couples the application specific module to the computer host, which provides user interface functions for the application.

This application is a continuation of application Ser. No. 09/309,373filed May 11, 1999 now U.S. Pat. No. 6,353,870.

FIELD

The invention is related to closed-case removable expansion cards forcomputer hosts, such cards having particular application to portablecomputer hosts such as handheld computing devices.

BACKGROUND

The broad use of portable host computers, including Personal DigitalAssistants (PDAs), has been severely hampered by limited capabilitiesfor expansion or customization. Expansion and application customizationhas been performed via only one, or at most two, slots for removableexpansion cards for I/O, I/O adapters, memories, and memory adapters.Memory expansion cards have included DRAM, SRAM, ROM, and Flashtechnologies. I/O expansion cards have included dedicated peripherals,networking, modems, wireless communications, serial I/O, and bar-codeand other scanners.

Having only one slot meant choosing between memory or peripheralexpansion. In two-slot implementations, one of the slots is generallyused for peripheral expansion, and the other for memory expansion. Asmarket forces and consumer demand are pushing future PDAs to be eversmaller, allocating packaging volume for two-slots will be increasinglyviewed as a costly and nonviable solution.

Memory and Expansion Card Standards

Two of the most popular industry standards for the slots and removablecards are the PC Card and the CompactFlash Card. The PC Card has a16-bit variant, previously known as a PCMCIA card, and a newer 32-bitvariant, also known as a Card-Bus card. U.S. Pat. No. 5,815,426 ('426),ADAPTER FOR INTERFACING AN INSERTABLE/REMOVABLE DIGITAL MEMORY APPARATUSTO A HOST DATA PART, assigned to Nexcom Technology, and herebyincorporated by reference, describes these and other removable expansioncard and memory types suitable for PDAs. In addition to the PC Card andCompactFlash Card formats, the '426 patent includes discussions of andreferences to Miniature Cards, Sold State Floppy Disk Cards (SSFDCs),MultiMediaCards (MMC), Integrated Circuit (IC) Cards (also known asSmart Cards), and Subscriber Identification Module (SIM) Cards.

CompactFlash Card

FIGS. 1A, 1B, and 1C are different views of a prior art Type IICompactFlash Card. The CompactFlash physical, electrical, and softwareinterface architecture is taught in the CompactFlash SpecificationRevision 1.3, Copyright 1998, by the CompactFlash Association, P.O. Box51537, Palo Alto, Calif. 94303, which is hereby incorporated byreference. FIGS. 1A, 1B, 1C, part of 6A, and part of 6B are reproducedor derived from the CompactFlash Specification document.

U.S. Pat. No. 5,887,145 ('145), REMOVABLE MOTHER/DAUGHTER PERIPHERALCARD, assigned to SanDisk Corporation, and hereby incorporated byreference, describes the required features of host systems forCompactFlash Cards, including controllers required by CompactFlashmemory cards (CF cards) and comprehensive controllers required byCompactFlash memory and I/O cards (CF+cards).

MultiMediaCard

FIGS. 2A and 2B represent a prior art MultiMediaCard form factor and itspad definitions. FIGS. 3A and 3B represent the prior art internalarchitecture of a generic MultiMediaCard and its registers. FIG. 4illustrates the prior art functional partitioning of a genericMultiMediaCard system. FIG. 5 illustrates the prior art physicalpartitioning of a generic MultiMediaCard system. The MMC and MMC relatedsystem issues are taught in the MultimediaCard System Summary Version2.0, Copyright January 1999, by the MultiMediaCard Association, 19672Stevens Creek Blvd., #404, Cupertino, Calif. 95014-2465, which is herebyincorporated by reference. FIGS. 2A, 2B, 3A, 3B, 4, 5, and part of 6Aare reproduced or derived from the MultimediaCard System Summarydocument.

FIGS. 6A and 6B are different views comparing the form factors of theprior art CompactFlash Card (top) and MultiMediaCard (bottom). In eachof 6A and 6B, the CompactFlash Card and the MultiMediaCard are bothroughly to equal scale.

Adapters for Removable Memories

Adapters exist or have been prophetically disclosed for physically andelectrically coupling a removable memory on a slide, or stick, to aportable host via a removable expansion card of either the PCMCIA Cardor CompactFlash Card form factors. The previously mentioned '426 patentdescribes such removable memory adapters. The focus of these existingmemory adapters has been limited to merely providing an interfaceadapter, or bridge, between a first interface type (the host toremovable-expansion-card interface) and a second interface type (theremovable memory stick).

PC Card Mother and CompactFlash Card Daughter Combinations

Adapters exist or have been prophetically disclosed that comprise aspecial mother PC Card designed to accept one or more daughterCompactFlash Cards of one or more types. The previously '145 patentdescribes such CompactFlash adapters. The focus of these existingmother/daughter combinations has also been limited. First, the daughtershave been used for memory expansion for the host platform, primarily inthe form of flash-memory-based mass-storage-like devices. In this firstapproach, the mother card provides the requisite mass-storage controllerfunctionality. Second, the daughters have been used for dedicatedperipheral, I/O, or communication functions. In this second approach,the mother card has a so-called comprehensive controller that augmentsthe mass-storage controller functionality with functions commonlyrequired or useful to multiple daughter cards. Third, in a variation ofeither of the first two paradigms, functions of the general-purpose hostmay be relocated to the mother card.

Background for PC-Card Based I/O Functions

Techniques are known in the art for making and using systems thatperform such I/O functions in a PC card. For example, see U.S. Pat. No.5,671,374 ('374), PCMCIA INTERFACE CARD COUPLING INPUT DEVICES SUCH ASBARCODE SCANNING ENGINES TO PERSONAL DIGITAL ASSISTANTS AND PALMTOPCOMPUTERS, assigned to TPS Electronics, which is hereby incorporated byreference. The '374 patent teaches the use of PDAs and similar hostsequipped with PC card interfaces for I/O devices including portablelaser-scanners, magnetic stripe and ink readers, keyboards and keypads,OCR devices, and trackballs.

Techniques are also known in the art for making and using PC Card-basedradios for applications based in a portable host. For example, see U.S.Pat. No. 5,519,577 ('577), SPREAD SPECTRUM RADIO INCORPORATED IN APCMCIA TYPE II CARD HOLDER, assigned to Symbol Technologies, and herebyincorporated by reference.

Techniques are also known in the art for making and using disk emulationdevices based on flash memory. For example, see U.S. Pat. No. 5,291,584('584), METHODS AND APPARATUS FOR HARD DISK EMULATION, assigned toNexcom Technology, and hereby incorporated by reference.

Background for Relevant Application Specific Functions

Techniques are known in the art for making and using systems thatdownload or capture compressed digital audio for storage and laterplayback using dedicated removable media. For example, U.S. Pat. No.5,676,734 ('734), SYSTEM FOR TRANSMITTING DESIRED DIGITAL VIDEO OR AUDIOSIGNALS, assigned to Parsec Sight/Sound, and hereby incorporated byreference, teaches a system for transmitting digital video or audiosignals over a telecommunications link from a first to a second party.In addition, U.S. Pat. No. 5,579,430 ('430), DIGITAL ENCODING PROCESS,assigned to Fraunhofer Gesellschaft zur Foerderung der angewandtenForschung e.V., and hereby incorporated by reference, teaches processesfor encoding digitized analog signals. Such processes are useful forinsuring high-quality reproduction while reducing transmission bandwidthand data storage requirements.

Techniques are also known in the art for making and using record andplayback portable host devices based on a dedicated flash memory. Forexample, see U.S. Pat. No. 5,491,774 ('774), HANDHELD RECORD ANDPLAYBACK DEVICE WITH FLASH MEMORY, assigned to Comp General Corporation,and hereby incorporated by reference, and U.S. Pat. No. 5,839,108('108), FLASH MEMORY FILE SYSTEM IN A HANDHELD RECORD AND PLAYBACKDEVICE, assigned to Norris Communications, also hereby incorporated byreference.

Limitations of Previous Approaches

In general purpose portable hosts, populating an expansion slot hasmeant choosing one of either removable memory or peripheral expansionfor that slot. When used for memory expansion, the removable memory hasbeen limited to use for the system or application software running onthe host. In essence, the removable memory has only been used ashost-dedicated memory. This was done either directly, e.g., as someportion of the main-memory of the host, or indirectly as an emulationsubstitute for host mass-storage (i.e., disk drives).

When used for I/O expansion, the expansion I/O-cards have not had accessto a private removable media/memory. This has prevented portablecomputer hosts, such as PDAs, from being used as a customizable platformfor many application-specific functions that require a removable memorydedicated to the application.

SUMMARY

The utility of portable computer hosts, such as PDAs, is enhanced bymethods and apparatus for closed-case removable expansion cards having aremovable memory in both a first and second embodiment. In both thefirst and second embodiments the closed-case removable expansion cardspreferably use a Type II CompactFlash form factor. In the firstembodiment the removable memory is in combination with an external-I/Oconnector or permanently attached external-I/O device, providing bothI/O and memory functions in a single closed-case removable expansioncard. This increases the expansion functional density for portablecomputer hosts, such as PDAs. That is, it increases the amount offunctionality that can be accommodated within a given volume allocationfor expansion devices. It also provides a viable alternative to 2-slotimplementations. In the second embodiment the removable memory is aprivate memory for application specific circuitry within theclosed-case-removable expansion card. This enhances the utility ofportable computer hosts, such as PDAs, as universal chassises forapplication specific uses. The standard CompactFlash physical andelectrical interface couples the application specific card to the host,which provides user interface functions for the application. The cardsinclude a top located slot and an internal connector for accepting aMultiMediaCard as the private removable memory. In addition, theapplication specific card will generally have some manner of I/O torequired external devices, such as scanning devices, sensors, ortransducers. Otherwise, all functionality for the application specificfunction is self-contained within the application specific card.Particular application specific cards for customizing general purposePDAs via the instant invention include a media-player card for digitizedmedia stored on removable memory and a bar-code-scanner card havingscanning data stored on removable memory.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A, 1B, and 1C are different views of a prior art Type IICompactFlash card.

FIGS. 2A and 2B represent a prior art MultiMediaCard form factor and itspad definitions.

FIGS. 3A and 3B represent the prior art internal architecture of ageneric MultiMediaCard and its registers.

FIG. 4 illustrates the prior art functional partitioning of a genericMultiMediaCard system.

FIG. 5 illustrates the prior art physical partitioning of a genericMultiMediaCard system.

FIGS. 6A and 6B compares the form factors of the prior art CompactFlashcard (top) and MultiMediaCard (bottom).

FIG. 7 illustrates a PDA equipped with a removable expansion card havingboth I/O and removable memory in accordance with the present invention.

FIG. 8 illustrates some of the various types of I/O for which the PDAand removable expansion card of FIG. 7 may be equipped.

FIG. 9 is an abstract drawing representing the removable expansion cardof FIG. 7 separate from the PDA, and with the I/O and memory disengagedfrom the removable expansion card.

FIG. 10 is an abstract drawing representing the construction detail ofthe upper and lower frame of the removable expansion card of FIG. 7.

FIG. 11 is an abstract drawing representing an exploded view of theremovable expansion card of FIG. 7, including the outer frame, innerPCB, and connectors.

FIG. 12A is an abstract drawing representing a view of the removableexpansion card of FIG. 7, with the outer frame removed, and a removablememory roughly aligned with the contact fingers to which it mates withinthe removable expansion card.

FIG. 12B is an abstract drawing representing a cut away side view of theremovable expansion card of FIG. 7, with the removable memory insertedinto the removable expansion card.

FIG. 13A is an abstract drawing representing an end view silhouette ofthe removable expansion card of FIG. 7.

FIG. 13B is an abstract drawing representing a cross-sectional viewsilhouette of the upper frame member of the removable expansion card ofFIG. 7.

DETAILED DESCRIPTION Components of the Expansion Card

FIG. 9 is an abstract drawing representing a closed-case removableexpansion card 100, i.e., an expansion card that may be inserted intoand removed out of a closed-case computer host. The card is especiallysuitable for use in a portable host, such as a PDA. In accordance withthe present invention, the expansion card of FIG. 9 includes a connector141 for I/O interconnect and a slot 121 for a removable memory. FIG. 9shows the I/O interconnect 140 and removable memory 120 disengaged fromthe removable expansion card.

FIG. 10 is an abstract drawing representing the construction detail ofthe upper 105 and lower 110 frame members of the removable expansioncard 100 of FIG. 9. An opening 111 is provided in the lower frame 110for receiving the connector 141 for I/O interconnect.

FIG. 11 is an abstract drawing representing an exploded view of theremovable expansion card 100 of FIG. 9, including the outer frame, innerPCB 115, and connectors. Visible for the first time in the view of FIG.11, a second opening 113 is provided in the lower frame 110 forreceiving the connector 150 for host interconnect. Additionally, a slot112 is provided on both sides of the opening 111 to aid in the alignmentand retention of the connector 141, and a slot 114 is provided on bothsides of opening 113 to aid in the alignment and retention of theconnector 150. An opening 116 is provided in the PCB for receiving theconnector 141.

FIG. 12A is an abstract drawing representing a view of the removableexpansion card 100 of FIG. 9, with the outer frame members removed, anda removable memory 120 roughly aligned with the contact fingers 180 towhich it mates within the removable expansion card. Circuitry 160 isprovided, including I/O adapter circuitry, removable memory adaptercircuitry, and application-specific circuitry. A support shelf 170supports, aligns, separates, and isolates the underside of the contactfingers 180 from the circuitry 160.

FIG. 12B is an abstract drawing representing a cut away side view of theremovable expansion card 100 of FIG. 9, with the removable memory 120inserted into the removable expansion card.

FIG. 13A is an abstract drawing representing an end view silhouette ofthe removable expansion card 100 of FIG. 9. FIG. 13B is an abstractdrawing representing a cross-sectional view silhouette of the upperframe member 105 of the removable expansion card 100 of FIG. 9. Guides190 provide alignment and support for removable memory inserted via slot121.

In a preferred embodiment, the expansion card 100 and associated hostconnector 150 are compatible with the Type II CompactFlash Card asdescribed in the previously referenced CompactFlash Specification. TheI/O connector 141 is compatible with a PC-Card industry standardHonda-style 15-pin connector. The slot 121, removable memory 120, andremovable memory adapter circuitry of circuitry 160, are compatible withthe MultiMediaCard as described in the previously referencedMultiMediaCard System Summary.

Circuitry on the Expansion Card

In a first embodiment of the invention, circuitry 160 includes I/Oadapter circuitry and removable memory adapter circuitry. The I/Oadapter functionality may include one or more of, but is not limited to,Ethernet, serial port, audio, telephone, antenna, and special-functioninterfaces such as bar code and other scanners. The removable memoryadapter functionality may include one or more of, but is not limited to,main memory expansion, mass-media emulation, and other host-basedspecial-purpose memory applications.

In accordance with a second embodiment, circuitry 160 further includesapplication-specific circuitry for which the management of the removablememory is an ancillary function to the primary function of the specificapplication. Specific examples of such application-specific expansioncards having both I/O and removable memory are provided in latersections.

In preferred implementations of both of the first and second embodimentsmentioned above, the functions performed by the removable memory arethose of a MultiMediaCard adapter as illustrated in the MultiMediaCardadapter section of the MultiMediaCard system architecture diagram ofFIG. 4. If the removable memory is being used to provide host-basememory expansion, such as described for the first embodiment, then thehost must provide the functionality illustrated by the Application andApplication Adapter sections of FIG. 4. If the removable memory is beingused at least sometimes as an ancillary memory (at least sometimesprivate) to the application-specific circuitry contained on theexpansion card, such as for the second embodiment, then theapplication-specific circuitry must provide the Application andApplication Adapter section functionality, or else theapplication-specific circuitry must call on host services for suchfunctionality.

Examples of known techniques for making and using other types of memoryadapter circuitry for closed-case expansion cards or with flash memoryare found in the previously referenced '145, '426, '584, '774, and '108patents, among others. Examples of known techniques for making and usingI/O adapter and application-specific circuitry for functions implementedin closed-case expansion cards and with flash memory are found in thepreviously referenced '374, '577, '774, and '108 patents, among others.

Frame Kit Assembly

The top and bottom frames may be composed of metal or plastic. In apreferred embodiment, the top and bottom frame portions each have aplastic base augmented with an outer metal plate over much of theinterior region of the large panel surface of each portion. The metalplate extends to the edges of the panel at the connector ends of eachportion and is attached to both connectors. In addition, smaller metalstrips, or ears, on both sides at the finger-grip end (opposite to thehost connector) extend from the plate to the edges of the panel andcontinue onto the sides. The frame kit is assembled and the side stripsare sonically welded together on both sides of the casings. The weldedstrips and plates form a single continuous metal band around the top andbottom frames that permanently physically retains the assembled kit.

I/O Interconnect Options

I/O devices may be interconnected with the expansion card via threedifferent embodiments. First, a PC-Card industry-standard Honda-style15-pin connector may be used with a mating detachable cable. Detachablecables are preferred for light-duty applications where a continuous I/Odevice connection is neither needed nor desired. Second, a fullyintegrated fixed cable, having a molded strain relief may be used. Sucha fixed cable maintains solid contact in high vibration environments, isprotected against lateral stress, and seals out dust. Fixed cables arepreferred for dedicated industrial or field applications. Third, atleast a portion of the I/O device may be abutted and attached (often viaa snap-in-place mechanism) directly to the expansion card, obviating theneed for either a detachable or fixed cable. Cableless snap-on I/Odevices are preferred for small mostly self-contained I/O devices thatpermit a compact PDA, expansion-card, I/O-device combination thathandles physically as a single piece of equipment. In the instantinvention, such snap-on I/O devices must make allowance for theremovable memory.

PDA having Application Specific Card with Removable Media

FIG. 7 illustrates a PDA 200 equipped with a removable expansion card100 having both I/O interconnect 140 and removable memory 120 inaccordance with the present invention. The application specificcircuitry of the expansion card may be used in conjunction withapplication specific software running on the PDA. This permits theapplication specific circuitry of the expansion card to make use of theoutput (e.g., display, sound) and input (e.g., tablet, buttons, any I/Oports) capabilities of the PDA for user interface functions associatedwith the specific application. In particular the PDA'sdisplay/input-tablet provides for virtual controls and visual indicatorsfor the application. FIG. 8 illustrates some of the various types of I/Ofor which the PDA and removable expansion card of FIG. 7 may beequipped. Application-specific functions may include special-functionmixed-signal electronics, special-function I/O, special-functiondata-pumps, and special-function accelerators.

Application Specific Embodiments Generic Removable Media Applications

The present invention enables general-purpose portable hosts to performapplication-specific functions requiring dedicated ROM. A first largeROM-based application category is that of prerecorded media, such asmusic, audio, video, and text (for books, newspapers, and otherpublications). A second large ROM-based application category iscustomization for programmable devices, such as games, languagetranslators, and other devices having “personality” modules.

The present invention also enables general-purpose portable hosts toperform application-specific functions requiring non-volatile read/writememory for data-capture, data-logging, data-checkpoints or backups,transaction logging, and data-transport.

In the illustrated embodiments the non-volatile read/write memory isflash memory in accordance with the standard MultiMediaCard. Suchremovable flash-memory-based application-specific functions haveparticular utility to medical and other data acquisition, securecommerce, financial and personal productivity devices making use ofunique removable memories for each of multiple individuals, projects, oraccounts.

The removable flash-based memory is also well suited where “sneaker-net”is a viable data transport. Provided manual/user intervention isacceptable, and depending on the speed of data link I/O incorporatedinto the expansion card, the physical transport of a removable memorydevice between a PDA-based expansion card and an external system mayprovide the best solution to fast local transport of large data-sets.For similar reasons, the use of removable memory devices may provide thebest solution to rapidly reconfiguring an application-specific expansioncard to initiate a large program or use a large data sets. The use oflabeled, color-coded, or otherwise distinctive, removable memory devicesalso may provide the best solution for ease of use for users needing toselect a particular program or data set from many for reconfiguring anapplication specific expansion card.

Specific Application Examples Media Player Application

The present invention permits a general purpose PDA to be customized(specially adapted) for use as a portable/wearable media player, at thehighest-level of functionality not unlike a portable Compact Diskplayer. Such a player uses the removable memory to store and playbackdigitally encoded media such as music, audio, or video. In a preferredembodiment the player makes use of the MPEG Layer 3 standard for digitalaudio encoding, generally known as MP3. Another embodiment makes use ofthe Microsoft Digital Audio standard. Other aspects of a preferredembodiment include an integral AM/FM receiver, a connector for a headsetwith an integral antenna for the receiver, and an auto-start on insertfeature that initiates the media playback upon insertion of theremovable memory. The PDA's display/input-tablet provides the virtualcontrols and visual indicators for the media player.

Module For Subscriber Services

In accordance with the present invention, an expansion card having I/Oand removable memory is inserted into a computer host. The I/O iscoupled to a receiver capable of receiving a large number of broadcastmessages and services. The removable memory contains subscriber servicesinformation for each individual user. The expansion card uses thesubscriber services information to filter out messages and services notapplicable to the present status of the subscriber. The PDA'sdisplay/input-tablet provides the virtual controls and visual indicatorsfor the display and access of captured messages and services.

Bar-Code Scanning Application (a Backup Storage Example)

In accordance with the present invention, an expansion card having I/Oand removable memory is inserted into a computer host, a bar-codingperipheral is connected to the I/O portion of the card, and a removablememory card is inserted into the memory slot of the card. After eachscan the scanned information is transferred through the I/O connectionto the host computer for processing. Additionally, a backup copy of thescanned information is stored on the removable memory. Should thecomputer host fail or should the operator need to verify scans, thebackup can be interrogated with the same or a different host.

Personal Environmental and Medical Monitoring Devices

The present invention permits a general purpose PDA to be customized asa portable/wearable personal environmental monitor. Equipped with theappropriate sensors and application-specific circuitry for sensor signalprocessing, such a device performs time-stamped data logging ofenvironmental attributes such as ionizing radiation, temperature, andhumidity. Similarly, a portable/wearable personal medial monitor datalogs health-related attributes such as pulse, temperature, respiration,and blood pressure. The PDA's display/input-tablet provides the virtualcontrols and visual indicators for the monitoring devices.

Automotive and Industrial Diagnostic Monitoring and Control

The combined I/O interconnect and removable memory of the presentinvention also permits a general purpose PDA to be customized (speciallyadapted) for use as a data logging diagnostic monitor or time-basedcontrol device. It is known that the diagnostic connectors of certainvehicles can be adapted to interface with PDAs for real-time monitoringof critical vehicle subsystems. The present invention permits suchdiagnostic monitoring data to be communicated via the I/O interconnectand logged to the removable memory. Such a tool facilitates trackingsubsystem performance over extended periods of time, and permitsreal-time and deferred graphics of time-varying system performanceattributes. The PDA's display/input-tablet provides the virtual controlsand visual indicators for the diagnostic monitor.

Conclusion

Although the present invention has been described using particularillustrative embodiments, it will be understood that many variations inconstruction, arrangement and use are possible within the scope of theinvention. For example the number of I/O interconnects, removablememories, contact fingers, number and type of application-specificcircuits, and the size, speed, and type of technology used may generallybe varied in each component of the invention. The invention is notlimited to the standard CompactFlash form factor, but other closed-caseremovable expansion card form factors are equally applicable. Nor is theinvention limited to use of the standard MultiMediaCard, as other typesof removable memory or media may also be employed. Functionallyequivalent techniques known to those skilled in the art may be employedinstead of those illustrated to implement various components. Thepresent invention is thus to be construed as including all possiblemodification and variations encompassed within the scope of the appendedclaims.

We claim:
 1. A removable expansion module for operation in a first slotof a portable host and in conjunction with other components including aremovable memory and a bar-coding peripheral, the removable expansionmodule comprising: an expansion module frame and PCB; I/O adaptercircuitry and I/O interconnect compatible with the bar-codingperipheral, the I/O interconnect providing first information transfersbetween the bar-coding peripheral and the module; a second slot for theremovable memory; removable memory adapter circuitry for providingsecond information transfers with the removable memory; and wherein atleast some of the information transfers include bar code relatedinformation, the first and second slot are respectively a first-leveland second-level slot, the module is a first-level module coupled to theportable host via the first-level slot, the removable memory is asecond-level module coupled to the first-level module via thesecond-level slot, and the second information transfers includetransferring information between the first-level module and thesecond-level module.
 2. The module of claim 1, wherein the module isphysically and electrically compatible with the CompactFlash industrystandard.
 3. The module of claim 1, wherein the second slot for theremovable memory is compatible with a MultiMediaCard, and the removablememory adapter circuitry is MultiMediaCard adapter circuitry.
 4. Themodule of claim 1, wherein the module is designed to abut and fastenwith at least part of the bar-coding peripheral such that theJIG-interconnect for coupling with the bar-coding peripheral iscableless.
 5. The module of claim 1, further including bar codeapplication-specific circuitry, and wherein the removable memory is aprivate memory for the application-specific circuitry, the management ofthe removable memory being an ancillary function to the primary functionof the specific application.
 6. The module of claim 5, wherein the I/Ocircuitry is coupled to the bar code application-specific circuitry andis not directly coupled to the portable host.
 7. The module of claim 1,wherein at least some of the first information transfers include barcode related information.
 8. The module of claim 1, wherein at leastsome of the second information transfers include bar code relatedinformation.
 9. The module of claim 8, wherein at least some of the barcode related information is written to the removable memory.
 10. Themodule of claim 9, wherein the information written to the removablememory corresponds at least in part to bar code related informationprovided via the first information transfers.
 11. The module of claim 8,wherein at least some of the bar code related information is read fromthe removable memory.
 12. The module of claim 1, further includingfirst-level slot interconnect, the first-level slot interconnectproviding third information transfers between the first-level module andthe portable host, and wherein at least some of the third informationtransfers include bar code related information.
 13. The module of claim12, wherein the bar code related information included in the thirdinformation transfers corresponds at least in part to bar code relatedinformation provided via the first information transfers.
 14. The moduleof claim 12, wherein the bar code related information included in thethird information transfers corresponds at least in part to informationread from the removable memory.
 15. The module of claim 14, wherein theinformation read from the removable memory corresponds at least in partto bar code related information previously provided via the firstinformation transfers.
 16. A method of customizing a PDA for bar codescanner functions, the method comprising: providing the PDA, the PDAhaving display and input devices and a first slot; providing the firstslot with an expansion module having a second slot, application-specificcircuitry for implementing at least part of the bar code scannerfunctions, and removable memory adapter circuitry; providing the secondslot with a removable memory, the removable memory adapter circuitryreading from and writing to the removable memory in accordance with thebar code scanner functions; providing application software for the PDAto provide user interface related bar code scanner functions using thedisplay and input devices of the PDA; providing an I/O device forgenerating bar code related information, providing an I/O adaptercompatible with the I/O device, the I/O adapter being integral to theexpansion module; providing I/O coupling from the I/O adapter to the I/Odevice, and transferring the bar code related information between theI/O device and the I/O adapter; and wherein the PDA is a portable host,the first and second slot are respectively a first-level andsecond-level slot, the expansion module is a first-level module coupledto the portable host via the first-level slot, the removable memory is asecond-level module coupled to the first-level module via thesecond-level slot, and the reading and writing operations includetransferring information between the first-level module and thesecond-level module.
 17. The method of claim 16, further includingtransferring bar code related information between the first-level moduleand the PDA.
 18. The method of claim 16, wherein at least part of theI/O device is abutted and fastened to the expansion module such that theI/O coupling is cableless.
 19. The method of claim 16, wherein theinformation transferred between the first-level module and thesecond-level module includes bar code related information.
 20. Themethod of claim 19, wherein at least some of the bar code relatedinformation is written to the removable memory.
 21. The method of claim20, wherein the information written to the removable memory correspondsat least in part to bar code related information provided to the I/Oadapter by the I/O device.
 22. The method of claim 19, wherein at leastsome of the bar code related information is read from the removablememory.
 23. The method of claim 17, wherein the bar code relatedinformation included in the transfers between the first-level module andthe PDA corresponds at least in part to bar code related informationprovided by the I/O device.
 24. The method of claim 17, wherein the barcode related information included in the transfers between thefirst-level module and the PDA corresponds at least in part toinformation read from the removable memory.
 25. The method of claim 24,wherein the information read from the removable memory corresponds atleast in part to bar code related information previously provided by theI/O device.
 26. A method of performing data transfers in a portablecomputing system, the method comprising: providing a first portablecomputing host having a first slot including an associated firstfirst-level expansion interface; providing an external bar code scannerI/O device; inserting a first first-level expansion module into thefirst slot and operatively coupling the first first-level expansionmodule to the first first-level expansion interface, the firstfirst-level expansion module having a first-level I/O interfacecompatible with the bar code scanner I/O device, and a second slotincluding an associated first second-level expansion interface; couplingthe bar code scanner I/O device to the first-level I/O interface;inserting a second-level expansion module having expansion memory intothe second slot and operatively coupling the second-level expansionmodule to the first second-level expansion interface; performing firstdata transfers over the first first-level expansion interface, the firstdata transfers being between the first portable computing host and thefirst first-level expansion module; performing second data transfersover the first-level I/O interface, the second data transfers being andbetween the first first-level expansion module and the bar code scannerI/O device; and performing third data transfers over the firstsecond-level expansion interface, the third data transfers being betweenthe first first-level expansion module and the second-level expansionmodule.
 27. The method of claim 26, further comprising: storing a backupcopy of at least a portion of the data contained in the second datatransfers to the expansion memory of the second-level expansion module.28. The method of claim 27, further comprising: reading at least aportion of the backup copy from the expansion memory.
 29. The method ofclaim 28, wherein the reading is performed while the second-levelexpansion module is inserted in the first first-level expansion module,and the first first-level expansion module is inserted in the firstportable computing host.
 30. The method of claim 28, further comprising:providing a second portable computing host having a third slot includingan associated second first-level expansion interface; removing the firstfirst-level expansion module from the first portable host; afterremoving the first first-level expansion module, then inserting thefirst first-level expansion module into the third slot and operativelycoupling the first first-level expansion module to the secondfirst-level expansion interface; and wherein the storing of the backupcopy is performed while the first first-level expansion module isinserted in the first slot, and the reading is performed while the firstfirst-level expansion module is inserted into the third slot.
 31. Themethod of claim 28, further comprising: providing a fourth slotassociated with an expansion interface compatible with the second-levelexpansion module; removing the second-level expansion module from thesecond slot; after removing the second-level expansion module, theninserting the second-level expansion module into the fourth slot andoperatively coupling the second-level expansion module to the compatibleexpansion interface; and wherein the storing of the backup copy isperformed while the second-level expansion module is inserted in thesecond slot, and the reading is performed while the second-levelexpansion module is inserted into the fourth slot.
 32. The method ofclaim 31, wherein the fourth slot and associated expansion interface areincluded in a PC.
 33. The method of claim 31, wherein the fourth slotand associated expansion interface are included in a PDA.
 34. The methodof claim 27, wherein the second data transfers include scanned bar codeinformation.
 35. A removable expansion module for operation in a firstslot of a portable host and in conjunction with other componentsincluding a removable memory and a bar code scanner, the removableexpansion module comprising: an expansion module frame and PCB, themodule having I/O circuitry compatible with the scanner, the modulehaving I/O interconnect compatible with the scanner, the I/Ointerconnect providing first information transfers between the scannerand the module, the module having a second slot for the removablememory, the module including removable memory adapter circuitry forproviding second information transfers with the removable memory, thefirst and second information transfers including scanner data; andwherein the first and second slot are respectively a first-level andsecond-level slot, the module is a first-level module coupled to theportable host via the first-level slot, the removable memory is asecond-level module coupled to the first-level module via thesecond-level slot, and the second information transfers includetransferring information between the first-level module and thesecond-level module.
 36. The module of claim 35, wherein the firstinformation transfers include scanned bar code information.
 37. Themodule of claim 35, wherein the second information transfers include barcode related information.
 38. The module of claim 37, wherein at leastsome of the bar code related information is written to the removablememory.
 39. The module of claim 38, wherein the information written tothe removable memory corresponds at least in part to scanned bar codeinformation provided via the first information transfers.
 40. The moduleof claim 37, wherein at least some of the bar code related informationis read from the removable memory.
 41. The module of claim 35, furtherincluding first-level slot interconnect, the first-level slotinterconnect providing third information transfers between thefirst-level module and the portable host, and wherein at least some ofthe third information transfers include bar code related information.42. The module of claim 41, wherein the bar code related informationincluded in the third information transfers corresponds at least in partto scanned bar code information provided via the first informationtransfers.
 43. The module of claim 41, wherein the bar code relatedinformation included in the third information transfers corresponds atleast in part to information read from the removable memory.
 44. Themodule of claim 43, wherein the information read from the removablememory corresponds at least in part to scanned bar code informationpreviously provided via the first information transfers.